Npower has hiked energy prices by 10.4% adding £135.7 to an average duel fuel bill which rises from £1,304.87 to £1,440.58

The cost of electricity is to rise by 9.3% while gas prices have lept by 11.1%.

Npower is the third ‘big six’ energy provider to announce price hikes affecting approximately 3.1 million customers.

SSE dealt consumers the first blow by announcing an 8.2% energy price rise on 10 October, followed one week later by the UK’s biggest energy company, British Gas, who went one better, doling out a 9.2% increase to its hard-pressed customers.

Now Npower has announced an even bigger price rise of 10.4%, which is due to take effect from 1 December, adding £135.71 to the average customer’s annual dual fuel energy bill.

Comparison site Gocompare has listed the rises so far.

Effect of winter energy price rises so far**

Supplier

Annual bill in August 2013

Price rise (%)

Annual bill after winter 2013 price rises

Difference (£)

British Gas

£1,311.48

9.2%

£1,432.14

+£120.66

SSE

£1,308.17

8.2%

£1,415.44

+£107.27

Npower

£1,304.87

10.2%

£1,440.58

+£135.71

E.ON

£1,315.33

TBC

TBC

TBC

EDF Energy

£1,291.55

TBC

TBC

TBC

Scottish Power

£1,319.70

TBC

TBC

TBC

Jeremy Cryer, energy spokesman at price comparison website Gocompare.com, said: “The floodgates have been well and truly opened, and with Npower’s price rise now confirmed, we’re half way towards a full-house of price rises from the big six energy providers.

“Winter price hikes are unwelcome, yet unfortunately entirely predictable. But it’s not over yet, and Scottish Power, E.ON and EDF will surely reveal their price hikes soon too. People who are concerned about their energy bills need to act now to find a better deal, and should strongly consider moving to a fixed tariff.

“There are dual fuel tariffs available at the moment from EDF and Scottish Power that are fixed until March 2017 and January 2017 respectively, and many others that allow you to fix well into 2015. Fixing, particularly long term, can be a gamble as you won’t benefit if any price reductions are introduced, but if you’re after consistent energy bills these sorts of tariffs mean that you needn’t worry about further price hikes for some time.

“Comparing tariffs from the big six energy companies, and the multitudes of other energy suppliers available, takes just minutes using a price comparison site, so it’s disheartening that just 14% of people have switched energy in the last year***. These winter price hikes are further proof, if it were needed, that the best way to take control of how much you spend on gas and electricity is to shop around regularly.”